It has been known that bis(fluorosulfonyl)imide ((FSO2)2NH) is an useful anion source for ion electrical conducting materials and ion liquids. As methods for producing bis(fluorosulfonyl)imide, there are methods disclosed in the Patent Literature (PTL) 1, the PTL2, Non-Patent Literature (NPL) 1, and NPL2.
In the NPL1, a method, in which urea (CO(NH2)2) and fluorosulfonic acid (FSO3H) are mixed first, and then the resulting mixture is heated to proceed the chemical reaction between them, is disclosed. In this reaction, the chemical reaction represented by the formula (1) below proceeds, producing bis(fluorosulfonyl)imide, ammonium hydrogen sulfate (NH4HSO4), hydrogen fluoride (HF), and carbon dioxide (CO2). The produced bis(fluorosulfonyl)imide and the fluorosulfonic acid that is input excessively can be recovered by distillation under reduced pressure.3FSO3H+CO(NH2)2→(FSO2)2NH+NH4HSO4+HF+CO2  (1)
In the NPL2, a method, in which bis(chlorosulfonyl)imide ((ClSO2)2NH) and arsenic trifluoride (AsF3) are reacted, is disclosed. In this reaction, the chemical reaction represented by the formula (2) below proceeds, producing bis(fluorosulfonyl)imide and arsenic trichloride (AsCl3).3(ClSO2)2NH+2AsF3→3(FSO2)2NH+2AsCl3  (2)
In the PTL1 and PTL2, methods, in which bis(chlorosulfonyl)imide and potassium fluoride (KF) are reacted, are disclosed. In this reaction, the chemical reaction represented by the formula (3) below proceeds, producing bis(fluorosulfonyl)imide and potassium chloride (KCl). In the method described in the PTL1, the bis(chlorosulfonyl)imide is subjected to fluorine displacement by potassium fluoride in a nitromethane solvent. In the method described in the PTL2, the bis(chlorosulfonyl)imide is subjected to fluorine displacement in the presence of a basic catalyst in an organic solvent by potassium fluoride.(ClSO2)2NH+2KF→(FSO2)2NH+2KCl  (3)Related Art DocumentPatent Literature
[PTL1] Published Japanese Translation No. 2004-522681
[PTL2] Japanese Unexamined Patent Application, First Publication No. 2007-182410
Non-Patent Literature
[NPL1] Chem. Bet 95, 246-8 (1962) (Appel&Eisenhauser)
[NPL2] Inorg. Synth. 11, 138-43 (1968)